Abstract 2028: Subendocardial Ischemia in Adults with Repaired Coarctation: A Potential Mechanism for Early Ischemic Events
Objectives: Despite earlier surgical repair in patients with coarctation of the aorta (CoA), early ischemic deaths affect adult survivors with no prospective data to explain these events. This study sought to identify potential ischemic substrate by examining coronary arteries and myocardial perfusion reserve in adults with repaired CoA.
Methods: Patients and controls underwent 64-slice computed tomography coronary angiography and cardiac magnetic resonance examination with rest/stress perfusion. Myocardial perfusion reserve index (MPRI) was quantified using the normalized upslope of myocardial signal enhancement with vasodilator stress versus rest.
Results: Twenty-seven subjects with repaired CoA and 10 controls completed the protocol. Subjects’ mean age and age of initial repair was 27.1±5 years and 5.6±5.6 years, respectively. The entire coronary tree was well-visualized in all subjects with no epicardial disease seen. CoA patients had marked perfusion abnormality with adenosine (Figure⇓). T-test analysis of MPRI revealed significant impairment in endocardial to epicardial perfusion reserve ratio in all CoA subjects compared to controls (p<0.0001). A trend toward statistical significance was noted for age (p=0.074) and older age at repair (p=0.064) as predictors of ischemia.
Conclusions: This comprehensive noninvasive assessment identified abnormal subendocardial perfusion reserve as potential substrate for ischemic heart disease in adults with repaired coarctation. These previously unrecognized findings in vivo warrant reevaluation of current follow-up strategies that have been inadequate in reducing ischemic deaths in this population.